Checked my CC statement and TAP only refunded a part of my total fee. The CC bank said to dispute the partial refund with TAP because they won't do a charge-back. ...?

So I made a dispute about the partial refund with TAP.
Sheesh, what a headache this is becoming...
Edit:
Today TAP said that IF I had asked for a voucher refund, all costs would have been "refunded on the voucher". Since I asked for a "money" refund, I was only returned. That situation/difference was not explained to me when I initially spoke to the CS agent when trying to change the d onomy flight to business.
Entrapment seems to be the legal term.
Also my credit card company in Canada does not want to do a charge back. Seems like it is time to change credit card companies. 🙄